Fork rebuild

[dna9656]

Does anyone have a comprehensive/complete list of recommended parts when installing new springs in the fork? Leak proof offers 2 different seals. Amazon doesn't recognize the Leakproof P/Ns. The Leakproof seals are on eBay. Besides Yamaha and Leakproof are there other sources for seals? Should I replace bushings and the spacers because I'm in the tubes anyway? My '88 has 65k miles on it, the forks bottom out pretty easily. Could this be the dampeners on the forks? If it is is there a venturerider easy solution /test to determine if the dampeners are at fault and therefor I wouldn't have to replace the springs? I could use some guidance and advice!

Edited June 12, 2018 by dna9656

[Patch]

Can you tell us if the front sits low?

 

When you compress the front does she respond quickly? (moving back up)

 

If you are willing to take the time to rebuild them then change all ware parts.

 

But check the lowers for ware as well. If the are very worn then that is problematic.

[dna9656]

Can you tell us if the front sits low?

 

When sitting on my 83 through 85 bikes I can touch the ground with my toes only, on the 88 I can lay my feet flat on the ground

 

When you compress the front does she respond quickly? (moving back up)

 

If you are willing to take the time to rebuild them then change all ware parts.

 

I'd like to take them apart ONE TIME only, replace all necessary wear /worn parts at the SAME time.

 

But check the lowers for ware as well. If the are very worn then that is problematic.

 

If by the term "lowers" you are referring to the UN-machined part of the fork that receives the polished fork tube as it goes up and down then no, I haven't inspected the "lowers". I can't find the name "lowers" in the parts fiche so I can only assume you're referring to the tube-ish cast part the brake caliper bolts to.

 

Thanks!

[Patch]

Funny guy.

 

The point is Doug, if the outer tubes are worn out, on the inside then changing the slide bush will improve them but...

 

The other point is if they spring back crisply/quickly then the springs may be fine, I don't know or have a spring length to refer to for a quick measurement.

 

Check the dive relays as well I think referred to as Eand.

[dna9656]

Funny guy.

 

The point is Doug, if the outer tubes are worn out, on the inside then changing the slide bush will improve them but...

 

The other point is if they spring back crisply/quickly then the springs may be fine, I don't know or have a spring length to refer to for a quick measurement.

 

Check the dive relays as well I think referred to as Eand.

 

I will check the fork spring back vitality tomorrow (Saturday) but I can tell you now that in comparison to my 83s to 85s the forks bottom out like there is VERY LITTLE spring action going on. A hefty bang is the results rolling over one of those concrete water troughs you find in asphalt parking lots at less than 5 mph; the trough is about 16" wide, and has the cross section of a soup bowl.

Tomorrow will tell....

 

Doug

[Patch]

Well if they are original to the bike Doug likely due to be changed.

 

I am a bit busy tomorrow may not be around to pitch in. However I have a set in the shop which I know were weak and I would like to measure them. I also have some dissembled forks I'll see what the lowers look like, if they are worn I'll forward a picture for comparing.

 

Here is what I remember about mine before I changed them up.... They would be slow to rise and would jerk a bit on the way back up.

They would bottom but it would need to be fairly steep.

 

What is your mileage? When you go over speed bumps usually your brakes are applied, so wondering what condition the anti dive relays are in?

Do you know how to check them?

[dna9656]

Well if they are original to the bike Doug likely due to be changed.

 

I am a bit busy tomorrow may not be around to pitch in. However I have a set in the shop which I know were weak and I would like to measure them. I also have some dissembled forks I'll see what the lowers look like, if they are worn I'll forward a picture for comparing.

 

Here is what I remember about mine before I changed them up.... They would be slow to rise and would jerk a bit on the way back up. They would bottom but it would need to be fairly steep.

 

 

What is your mileage?

 

When you go over speed bumps usually your brakes are applied, so wondering what condition the anti dive relays are in?

 

Do you know how to check them? No.

 

Mileage 66k

 

I didn't go over a speed bump I drove over a water drain; think of a " ( " but rotate it so it looks like a smile and put a row of this made of concrete 16" wide and placed in the center of a parking lot; think of a "V" roof, the drain would be at the bottom of the "V".

 

I exp. the bottoming out while riding, slowly at 5 mph, while the bike was moving I'm sure the forward momentum had some effect on how fast the forks recovered. I will check tomorrow and maybe send you a vid if I can get some help...

 

I have no idea of the condition of the anti-dive units but it seems to me that even if they were disabled the forks would not bottom out so flatly, I mean it's like there is no oil in a shock absorber, just BANG they bottom out. If the springs were any good at all there would be some sort of resilience would there?...

 

I appreciate your input and offer of assistance!

[Patch]

I understand Doug.

 

I am going to try to explain in a basic format the complex yet simplicity of forks.

 

The springs are less than 1/2 the value. Simply put they provide the brute forces.

There is a lot of gyro force that is included in the design of the forks. So another important item is oscillation. In reality these are the most important designs concerns.

 

So keeping it basic- on mine I had a problem with high speed wobble, not a very technical term; however for those of us unfortunates that know what this experience is, quite spooky!

 

Breaking it down wasn't hard I built frequency and what ever tipped it into wobble. ( its a high speed thing)

 

Without going into too much detail the forward height must be balanced. Thee spring has to keep the extension or form, so it too is tuned via progression. Progression can be long or short and anything in between.

 

So again we expect the spring to absorb energy, then we expect the spring to maintain form. This is a part of spring design and the other most important is heat treating!!!

 

The complexity is really in torsion/twist and dampening. When you crash, the length of travel exceeds expectation, you have in effect applied to much force or possibly exceeded duty cycles! What really happens is the dampening failed the spring "usually" that is assuming the spring is still within design spec, or has not yet exceeded duty cycle

 

So again (yah I know I say- so- a lot) we ride sport machines not family vans! The forks are very important and worth every penny to maintain! There is zero reasoning for power when we as pilot can completely dominate, ok control- it!

keeping it simple take a rather large rubber band, between to extended fingers stretching the band with elbows bent out- the band is the spring the supraspinatus, infraspinatus, subscapularis, and teres are the dampening forces or balance!

 

Good night

Patch

[dna9656]

I understand Doug.

 

I am going to try to explain in a basic format the complex yet simplicity of forks.

 

The springs are less than 1/2 the value. Simply put they provide the brute forces.

There is a lot of gyro force that is included in the design of the forks. So another important item is oscillation. In reality these are the most important designs concerns.

 

So keeping it basic- on mine I had a problem with high speed wobble, not a very technical term; however for those of us unfortunates that know what this experience is, quite spooky!

 

Breaking it down wasn't hard I built frequency and what ever tipped it into wobble. ( its a high speed thing)

 

Without going into too much detail the forward height must be balanced. Thee spring has to keep the extension or form, so it too is tuned via progression. Progression can be long or short and anything in between.

 

So again we expect the spring to absorb energy, then we expect the spring to maintain form. This is a part of spring design and the other most important is heat treating!!!

 

The complexity is really in torsion/twist and dampening. When you crash, the length of travel exceeds expectation, you have in effect applied to much force or possibly exceeded duty cycles! What really happens is the dampening failed the spring "usually" that is assuming the spring is still within design spec, or has not yet exceeded duty cycle

 

So again (yah I know I say- so- a lot) we ride sport machines not family vans! The forks are very important and worth every penny to maintain! There is zero reasoning for power when we as pilot can completely dominate, ok control- it!

keeping it simple take a rather large rubber band, between to extended fingers stretching the band with elbows bent out- the band is the spring the supraspinatus, infraspinatus, subscapularis, and teres are the dampening forces or balance!

 

Good night

Patch

 

You must be a Doc or a massage therapist!

[dna9656]

Funny guy.

 

The point is Doug, if the outer tubes are worn out, on the inside then changing the slide bush will improve them but...

 

The other point is if they spring back crisply/quickly then the springs may be fine, I don't know or have a spring length to refer to for a quick measurement.

 

Check the dive relays as well I think referred to as Eand.

 

Fork spring length on the 88 is 18" or 456.5mm.

[dna9656]

Can you tell us if the front sits low?

 

When you compress the front does she respond quickly? (moving back up)

 

If you are willing to take the time to rebuild them then change all ware parts.

 

But check the lowers for ware as well. If the are very worn then that is problematic.

 

The rebound seems normal to me, I read the inspection requirements for the fork rebuild in the 1300 supplement manual, They do not inspire much confidence, i saw nothing on how to check the anti dive units.

[Patch]

Good morning Doug,

 

I did try to catch up a little last night and thought it best to wait till morning.

I am a project guy, I receive input many times during the course of a working day Often find it helps to simplify information while keeping in mind expressed concerns. The very big problem for me is spelling out what comes so easy to me when expresses verbally!

 

The anti dive aren't difficult to check, in my opinion should not be bypassed, should be maintained. Now I'm going to explain what your mind and reflex all ready know. When you run quickly and want to or need to stop suddenly; do you lean forward or instinctively ignite the kinetic springs taking a reverse lean? That is an electric impulse sent through the nervous system, same exact thing for the anti dive units!

They slow the front compression which in turn helps the front tire maintain "form" and very importantly maintain the rear tire patch grip by slowing the forward motion of CG.

 

This is the very reason for the "designed" interlock braking system on this beast of a machine.

 

Next the supplement, I don't think I've read it? I use the hard copy and use it for order of... and design tolerances. I am lucky enough to be able to see improvement potential based 1 on experience, and 2 as a challenge; everything can be improved and is why I enjoy old bikes and cars!

 

So where are we at the moment with the forks? What can I do for you to help you get started?

 

I noticed in a post that Freebird recommends a different brand spring for the gen 2. So begs the question, has he been bribed by another brand, could be? Just look at all the advertisements we have to put up with on this forum;) Or is the recommendation based on experiment, fine tuning and shared experience? Hmmm

 

Everything wares out. Feet flat on the ground, how tall are you? My feet are flat to the ground on mine and that is what I want, she's heavy. How many mile on this bike?

[dna9656]

Good morning Doug,

 

I did try to catch up a little last night and thought it best to wait till morning.

I am a project guy, I receive input many times during the course of a working day Often find it helps to simplify information while keeping in mind expressed concerns. The very big problem for me is spelling out what comes so easy to me when expresses verbally!

 

The anti dive aren't difficult to check, in my opinion should not be bypassed, should be maintained. Now I'm going to explain what your mind and reflex all ready know. When you run quickly and want to or need to stop suddenly; do you lean forward or instinctively ignite the kinetic springs taking a reverse lean? That is an electric impulse sent through the nervous system, same exact thing for the anti dive units!

They slow the front compression which in turn helps the front tire maintain "form" and very importantly maintain the rear tire patch grip by slowing the forward motion of CG.

 

This is the very reason for the "designed" interlock braking system on this beast of a machine.

 

Next the supplement, I don't think I've read it? I use the hard copy and use it for order of... and design tolerances. I am lucky enough to be able to see improvement potential based 1 on experience, and 2 as a challenge; everything can be improved and is why I enjoy old bikes and cars!

 

So where are we at the moment with the forks? What can I do for you to help you get started?

 

I noticed in a post that Freebird recommends a different brand spring for the gen 2. So begs the question, has he been bribed by another brand, could be? Just look at all the advertisements we have to put up with on this forum;) Or is the recommendation based on experiment, fine tuning and shared experience? Hmmm

 

Everything wares out. Feet flat on the ground, how tall are you? My feet are flat to the ground on mine and that is what I want, she's heavy. How many mile on this bike?

 

 

The forks on on the bike, I pushed down on the handlebars while the bike was on the center stand,spring back seems normal to me...I was looking for a list of parts like seals, bushes (bushings?) that can be replaced while the fork assembly is apart.

The bike is a 88 Venture (not royal) with 66k miles on it. I'm 5'7" tall, I got a 30" inseam.

[Patch]

The center doesn't doesn't belong in the mix.

 

I can put together the list for you to shop around.

[Patch]

Refer to post 19

 

 

 

Refer to page 6-32

 

3: o-ring 4

 

28 ounces of oil in total or measure down. The closer you get the rebuild to standard specs then the liter the oil you can choose, minimum is 10W

Regarding Eand units, they are check by applying voltage. They should buzz with either brake is apppied.

 

Roll the inner tubes on a flat surface checking for a smooth roll. If not replace or bring to a hydraulic service shop for straightening.

 

Poor the contents of the outer forks into a clean container, then stain looking for bits of metal or rubber. You will likely find the crash issues lying in the bottom of the outer tubes.

 

Regarding springs, once you get this far you are likely best served by replacing them.

 

Note: if you see excessive ware on the inner bore of the outer tubes, look into replacing them.

Edited June 11, 2018 by Patch

[dna9656]

ITEM QUANTY refer to page 6-36

 

1: OIL SEAL 2

3: SLIDE BUSH 2

4: GUIDE BUSH 2

5: OIL LOCK PIECE 2 LIKELY REQUIRED

 

Note don’t mix up the special washers

 

 

Refer to page 6-32

 

3: o-ring 4

 

28 ounces of oil in total or measure down. The closer you get the rebuild to standard specs then the liter the oil you can choose, minimum is 10W

Regarding Eand units, they are check by applying voltage. They should buzz with either brake is applied.

 

Roll the inner tubes on a flat surface checking for a smooth roll. If not replace or bring to a hydraulic service shop for straightening.

 

Poor the contents of the outer forks into a clean container, then stain looking for bits of metal or rubber. You will likely find the crash issues lying in the bottom of the outer tubes.

 

Regarding springs, once you get this far you are likely best served by replacing them.

 

Note: if you see excessive ware on the inner bore of the outer tubes, look into replacing them.

 

I'm having a very hard time isolating these 4 parts on the exploded parts diagram at partzilla.com.

Can some one give me a hand please?

Also on the parts Fitch; there are index (index numbers are associated with the part shown by the line that is drawn between the item (or part) and the index number) numbers with decimals... I don't follow that..... Also the names of the parts recommended for replacement in the service manual are not the same names used in the parts catalog.

 

https://www.partzilla.com/catalog/yamaha/motorcycle/1988/xvz13u/front-fork

Edited June 10, 2018 by dna9656
more information

[Patch]

I'll take a look

[BlueSky]

I don't know if this video will help but?

 

[Patch]

I’ll post a thread on what I’ve found, but here is what I believe is the best option.

 

Race Tech: To deal with the dive problem Gold Valve Emulator with potential for tuning. In some cases this may be all that your ride needs?

 

 

Gold Valve Emulator # FEGVS 3801 $170.00 Set

Bushings inner # FMBI 40201P $24.00 Set

Outer # FMBO 40122P $60.00 Set

Copper washers # HMWC 1015 $5.00 ea.

Oil seals # FKOS 40P $30.00 Set

Dust seals # FKDS 40P $30.00 Set

Springs 200lb rider .95 #FRSPS 3234 $130.00 Set

 

The spring rating is .80-.85-.90-.95-1.0 KG per MM.

Preload is 25MM or 1” below end cap

Recommend oil with Valve Emulator 15W

 

In all cases the outer/lower tubes must be in good order. If minimum ware is visual I would increase W

 

This link to their Venture page. Thier phone number is (951 279 6655)

http://www.racetech.com/ProductSearch/12/Yamaha/XVZ1300%20Venture/1987-91

 

 

Patch

[Patch]

Addressing a couple of PM's

 

I get the confusion on the parts lists that is shown pretty much on the commonly used net stores.

Here is one example: Item 13.43 (link below) read this as either line 13 or line 43!

You'll notice that both lines do not have a price or a QTY. this is because that is an oem list.

If we are looking for parts for a 20 or 30 year old bike we need to expand past the oem and look for other compatible merchandise; like in this case choosing a spring manufacture that meets your particular requirements, such as budget availability or performance')

 

https://www.cheapcycleparts.com/oemparts/a/yam/50042d35f8700209bc789f16/front-fork

 

parts list from post 19

Gold Valve Emulator # FEGVS 3801 $170.00 Set

Bushings inner # FMBI 40201P $24.00 Set ******

Outer # FMBO 40122P $60.00 Set

Copper washers # HMWC 1015 $5.00 ea.

Oil seals # FKOS 40P $30.00 Set

Dust seals # FKDS 40P $30.00 Set

Springs 200lb rider .95 #FRSPS 3234 $130.00 Set

 

Number 2 "Bush or Bushings Inner" not available from any supplier that I have checked.

Working with Race Tech they put me onto a bushing list by metrics; so as I've mentioned I have some spare forks I need to go through those parts measure the inner's then compare hopefully find a match that was produced for a different model!??

If I'm lucky enough to match the metrics then I'll post the part number.

 

Just an opinion, if you have recent springs regardless of MFG ; but you are still searching to solve dive with just oil W.

Consider the Emulator as a likely fix to the problem, and it's adjustable... Might be less expensive else where which is fine but who will support it, if you have problems.

 

As I mentioned before this setup will likely offer good performance, it would be where my money would go, if I were today looking at rebuilding. I have already rebuilt but the time to experiment was a pain in the ass! Race Tech are betting that their spring will perform better because it is a "true" coil once you have preloaded it! In other words it is not progressive.

 

Cheers

Patch